1# -*- Python -*- vim: set syntax=python tabstop=4 expandtab cc=80:
2#===----------------------------------------------------------------------===##
3#
4# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5# See https://llvm.org/LICENSE.txt for license information.
6# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7#
8#===----------------------------------------------------------------------===##
9"""
10diff - A set of functions for diff-ing two symbol lists.
11"""
12
13from libcxx.sym_check import util
14
15
16def _symbol_difference(lhs, rhs):
17    lhs_names = set(((n['name'], n['type']) for n in lhs))
18    rhs_names = set(((n['name'], n['type']) for n in rhs))
19    diff_names = lhs_names - rhs_names
20    return [n for n in lhs if (n['name'], n['type']) in diff_names]
21
22
23def _find_by_key(sym_list, k):
24    for sym in sym_list:
25        if sym['name'] == k:
26            return sym
27    return None
28
29
30def added_symbols(old, new):
31    return _symbol_difference(new, old)
32
33
34def removed_symbols(old, new):
35    return _symbol_difference(old, new)
36
37
38def changed_symbols(old, new):
39    changed = []
40    for old_sym in old:
41        if old_sym in new:
42            continue
43        new_sym = _find_by_key(new, old_sym['name'])
44        if (new_sym is not None and not new_sym in old
45                and old_sym != new_sym):
46            changed += [(old_sym, new_sym)]
47    return changed
48
49
50def diff(old, new):
51    added = added_symbols(old, new)
52    removed = removed_symbols(old, new)
53    changed = changed_symbols(old, new)
54    return added, removed, changed
55
56
57def report_diff(added_syms, removed_syms, changed_syms, names_only=False,
58                demangle=True):
59    def maybe_demangle(name):
60        return util.demangle_symbol(name) if demangle else name
61
62    report = ''
63    for sym in added_syms:
64        report += 'Symbol added: %s\n' % maybe_demangle(sym['name'])
65        if not names_only:
66            report += '    %s\n\n' % sym
67    if added_syms and names_only:
68        report += '\n'
69    for sym in removed_syms:
70        report += 'SYMBOL REMOVED: %s\n' % maybe_demangle(sym['name'])
71        if not names_only:
72            report += '    %s\n\n' % sym
73    if removed_syms and names_only:
74        report += '\n'
75    if not names_only:
76        for sym_pair in changed_syms:
77            old_sym, new_sym = sym_pair
78            old_str = '\n    OLD SYMBOL: %s' % old_sym
79            new_str = '\n    NEW SYMBOL: %s' % new_sym
80            report += ('SYMBOL CHANGED: %s%s%s\n\n' %
81                       (maybe_demangle(old_sym['name']),
82                        old_str, new_str))
83
84    added = bool(len(added_syms) != 0)
85    abi_break = bool(len(removed_syms))
86    if not names_only:
87        abi_break = abi_break or len(changed_syms)
88    if added or abi_break:
89        report += 'Summary\n'
90        report += '    Added:   %d\n' % len(added_syms)
91        report += '    Removed: %d\n' % len(removed_syms)
92        if not names_only:
93            report += '    Changed: %d\n' % len(changed_syms)
94        if not abi_break:
95            report += 'Symbols added.'
96        else:
97            report += 'ABI BREAKAGE: SYMBOLS ADDED OR REMOVED!'
98    else:
99        report += 'Symbols match.'
100    is_different = abi_break or bool(len(added_syms)) \
101                   or bool(len(changed_syms))
102    return report, abi_break, is_different
103